1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (c) 2011, NVIDIA Corporation.
4 */
5
6 #include <linux/init.h>
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/rfkill.h>
11 #include <linux/of.h>
12 #include <linux/platform_device.h>
13 #include <linux/clk.h>
14 #include <linux/slab.h>
15 #include <linux/acpi.h>
16 #include <linux/gpio/consumer.h>
17
18 struct rfkill_gpio_data {
19 const char *name;
20 enum rfkill_type type;
21 struct gpio_desc *reset_gpio;
22 struct gpio_desc *shutdown_gpio;
23
24 struct rfkill *rfkill_dev;
25 struct clk *clk;
26
27 bool clk_enabled;
28 };
29
rfkill_gpio_set_power(void * data,bool blocked)30 static int rfkill_gpio_set_power(void *data, bool blocked)
31 {
32 struct rfkill_gpio_data *rfkill = data;
33
34 if (!blocked && !IS_ERR(rfkill->clk) && !rfkill->clk_enabled) {
35 int ret = clk_enable(rfkill->clk);
36
37 if (ret)
38 return ret;
39 }
40
41 gpiod_set_value_cansleep(rfkill->shutdown_gpio, !blocked);
42 gpiod_set_value_cansleep(rfkill->reset_gpio, !blocked);
43
44 if (blocked && !IS_ERR(rfkill->clk) && rfkill->clk_enabled)
45 clk_disable(rfkill->clk);
46
47 rfkill->clk_enabled = !blocked;
48
49 return 0;
50 }
51
52 static const struct rfkill_ops rfkill_gpio_ops = {
53 .set_block = rfkill_gpio_set_power,
54 };
55
56 static const struct acpi_gpio_params reset_gpios = { 0, 0, false };
57 static const struct acpi_gpio_params shutdown_gpios = { 1, 0, false };
58
59 static const struct acpi_gpio_mapping acpi_rfkill_default_gpios[] = {
60 { "reset-gpios", &reset_gpios, 1 },
61 { "shutdown-gpios", &shutdown_gpios, 1 },
62 { },
63 };
64
rfkill_gpio_acpi_probe(struct device * dev,struct rfkill_gpio_data * rfkill)65 static int rfkill_gpio_acpi_probe(struct device *dev,
66 struct rfkill_gpio_data *rfkill)
67 {
68 const struct acpi_device_id *id;
69
70 id = acpi_match_device(dev->driver->acpi_match_table, dev);
71 if (!id)
72 return -ENODEV;
73
74 rfkill->type = (unsigned)id->driver_data;
75
76 return devm_acpi_dev_add_driver_gpios(dev, acpi_rfkill_default_gpios);
77 }
78
rfkill_gpio_probe(struct platform_device * pdev)79 static int rfkill_gpio_probe(struct platform_device *pdev)
80 {
81 struct rfkill_gpio_data *rfkill;
82 struct gpio_desc *gpio;
83 const char *name_property;
84 const char *type_property;
85 const char *type_name;
86 int ret;
87
88 rfkill = devm_kzalloc(&pdev->dev, sizeof(*rfkill), GFP_KERNEL);
89 if (!rfkill)
90 return -ENOMEM;
91
92 if (dev_of_node(&pdev->dev)) {
93 name_property = "label";
94 type_property = "radio-type";
95 } else {
96 name_property = "name";
97 type_property = "type";
98 }
99 device_property_read_string(&pdev->dev, name_property, &rfkill->name);
100 device_property_read_string(&pdev->dev, type_property, &type_name);
101
102 if (!rfkill->name)
103 rfkill->name = dev_name(&pdev->dev);
104
105 rfkill->type = rfkill_find_type(type_name);
106
107 if (ACPI_HANDLE(&pdev->dev)) {
108 ret = rfkill_gpio_acpi_probe(&pdev->dev, rfkill);
109 if (ret)
110 return ret;
111 }
112
113 rfkill->clk = devm_clk_get(&pdev->dev, NULL);
114
115 gpio = devm_gpiod_get_optional(&pdev->dev, "reset", GPIOD_ASIS);
116 if (IS_ERR(gpio))
117 return PTR_ERR(gpio);
118
119 rfkill->reset_gpio = gpio;
120
121 gpio = devm_gpiod_get_optional(&pdev->dev, "shutdown", GPIOD_ASIS);
122 if (IS_ERR(gpio))
123 return PTR_ERR(gpio);
124
125 rfkill->shutdown_gpio = gpio;
126
127 /* Make sure at-least one GPIO is defined for this instance */
128 if (!rfkill->reset_gpio && !rfkill->shutdown_gpio) {
129 dev_err(&pdev->dev, "invalid platform data\n");
130 return -EINVAL;
131 }
132
133 ret = gpiod_direction_output(rfkill->reset_gpio, true);
134 if (ret)
135 return ret;
136
137 ret = gpiod_direction_output(rfkill->shutdown_gpio, true);
138 if (ret)
139 return ret;
140
141 rfkill->rfkill_dev = rfkill_alloc(rfkill->name, &pdev->dev,
142 rfkill->type, &rfkill_gpio_ops,
143 rfkill);
144 if (!rfkill->rfkill_dev)
145 return -ENOMEM;
146
147 ret = rfkill_register(rfkill->rfkill_dev);
148 if (ret < 0)
149 goto err_destroy;
150
151 platform_set_drvdata(pdev, rfkill);
152
153 dev_info(&pdev->dev, "%s device registered.\n", rfkill->name);
154
155 return 0;
156
157 err_destroy:
158 rfkill_destroy(rfkill->rfkill_dev);
159
160 return ret;
161 }
162
rfkill_gpio_remove(struct platform_device * pdev)163 static int rfkill_gpio_remove(struct platform_device *pdev)
164 {
165 struct rfkill_gpio_data *rfkill = platform_get_drvdata(pdev);
166
167 rfkill_unregister(rfkill->rfkill_dev);
168 rfkill_destroy(rfkill->rfkill_dev);
169
170 return 0;
171 }
172
173 #ifdef CONFIG_ACPI
174 static const struct acpi_device_id rfkill_acpi_match[] = {
175 { "BCM4752", RFKILL_TYPE_GPS },
176 { "LNV4752", RFKILL_TYPE_GPS },
177 { },
178 };
179 MODULE_DEVICE_TABLE(acpi, rfkill_acpi_match);
180 #endif
181
182 static const struct of_device_id rfkill_of_match[] __maybe_unused = {
183 { .compatible = "rfkill-gpio", },
184 { },
185 };
186 MODULE_DEVICE_TABLE(of, rfkill_of_match);
187
188 static struct platform_driver rfkill_gpio_driver = {
189 .probe = rfkill_gpio_probe,
190 .remove = rfkill_gpio_remove,
191 .driver = {
192 .name = "rfkill_gpio",
193 .acpi_match_table = ACPI_PTR(rfkill_acpi_match),
194 .of_match_table = of_match_ptr(rfkill_of_match),
195 },
196 };
197
198 module_platform_driver(rfkill_gpio_driver);
199
200 MODULE_DESCRIPTION("gpio rfkill");
201 MODULE_AUTHOR("NVIDIA");
202 MODULE_LICENSE("GPL");
203